Misc questions

[routeconverter]

As per Wikipedia *.gpx files can contain all three types <wpt> and <rte> and <trk> several times.

That is correct.

It appears to me that all position lists of type 'Wapoint list' in a *.gpx file are handled together.

That is correct.

So (Christian may correct me) here we seem to face a limitation in the *.gpx file format.

That is correct. <wpt> doesn't have a structure that allows for multiple lists like <rte> and <trk> but it simply stored waypoints.